Ratchet mechanism



March 23, 1943.

K. R. LARSON ETAL RATCHET MECHANISM Filed April 2, 1941 INVENTORS. KENNETH R. LARSON.

EORGE M. WA AVEN. @i

ATTORNEY.

Patented Mar. 23, 1943 RATCHET MECHANISM Kenneth R. Larson, Des Plaines, Ill., and George M. Walraven, Kenosha, Wis., assignors to Snap- On Tools Corporation, Kenosha, Wis.

Application April 2, 1941, Serial No. 386,563

15 Claims.

This invention relates to ratchet devices and more particularly to reversible ratchets for wrenches, although certain features thereof may be employed with equal advantage for other purposes.

It contemplates more especially the provision of an improved ratchet device capable of instantaneous adjustment to enable reversal by withdrawal or change in position and its application for nut turning or other purposes.

Numerous types of reversible ratchet devices have heretofore been proposed, but these have not proven entirely satisfactory for special type wrenches wherein the nut turning or head member must be of an unusually large capacity and ofiers restrictions in both space and head size that does not accommodate the usual known type of ratchets. Torque Wrenches present such special problems in the head member in that a beam or other torque resisting member usually is connected to the head or nut turning member to preclude the accommodation of known types of ratchets. The head member in torque wrenches carries the entire torque resisting load and presents a limited space for the incorporation of ratchets. This coupled with the fact that such wrenches must be of durable construction and usually have a beam extending through the entire head, further complicates the adaptation of ratohets thereto A torque wrench of the type that presents a ratchet problem is fully described in copending application serially numbered 374,362 and filed January 14, 1941.

One object of the present invention is to sim plify the construction and improve the operation of devices of the character mentioned.

Another object is to provide a dependable ratchet mechanism that can be incorporated into a nut turning or other type of head member presenting limited space and special operating instrumentalities that preclude the adaptation of ratchets of standard or known design.

Still another object is to provide an improved ratchet member embodying a plurality of pawls that are circumferentially spaced to provide registry with a ratchet plate comprising part of a turning member.

A further object is to provide a plurality of circumferentially spaced pawls that are operatively connected to a positioned actuator to place certain pawls in and out of registry with a ratchet plate for operative engagement therewith.

A still further object is to provide a plurality of sets of pawls journalled in the head member parallel to the axis of rotation for operative engagement with a ratchet head comprising part of a turning member.

Still a further object is to provide a plurality of sets of pawls operatively connected with a positioned actuator for controlled directional engagement with a ratchet head comprising part of a turning member. 7 v 7 An additional object is to provide a plurality of opposite sets of pawls journalled in a head member parallel to the axis of rotation thereof for selected registry with circumferentially spaced pawl engaging members on a revoluble turning member for engagement by one or the other of. the sets of correspondingly opposite pawls.

Other objects and advantages will appear from the following description of an illustrative embodiment of the present invention.-

In the drawing: 7

Figure 1 is a plan view of a turning head member shown in association with a fragmentary dotted outline of a torque wrench handle and measuring instrumentalities. a

Figure 2 is a sectional view taken substantially along line II-II of Figure 1.

Figure 3 is a bottom plan View of the turning head member shown in Figures 1 and 2.

Figure 4. is a sectional view in elevation taken substantially along line IV-IV of Figure 1 with provision for receiving a torque beam or turning rod depending upon the type of wrench or the purpose for which it is designed.

Figure 5 is a sectional view in elevation taken substantially along line V-V of Figure 1.

Figure 6 is a perspective view in elevation of a pawl taken at a slight angle or upon the ratchet engaging face thereof, this particular .type of pawl being shown in assembled association in Figure 5.

Figure 7 is a sectional plan view taken substantially along line VII-VII of Figure 5.

Figure 8 is a sectional View taken substantially'along line'VIIIVIII of Figure 5.

The'structure selected for illustration is shown in association with a torque wrench body member IE] to present a torque resisting beam ll shown in dotted outline together with the casing I0 for reception and operative connection of the head member I 2. The head member 12 is, in this instance, of cylindrical configuration (Figure 5) for telescopic association with a correspondingly shaped recess l3 provided in the open end M of the casing Ill. The headmember I2 is, for the main part, of solid construction and presents an elongated cylindrical bore I5 that, is drilled or otherwise provided entirely through the head member 12 along a median line normal to its axis and substantially equi-distant from the top and bottom surfaces It and I1 thereof.

The elongated bore I5 is sized to receive the torque resisting beam H which is press fitted therein for secure attachment to functionally serve as an integral part thereof. This is desirable in head members l2 adapted for torque wrenches that present the unusual problem for the adaptation of a ratchet mechanism thereto. The head member i2 is operatively connected to the load or element that is to be turned. To this end, the turning shank I8 of cylindrical configuration has a peripheral shoulder l9 formed thereon to merge with a circular flange 25 constituting an integral part thereof to substantially define the circular plate. So that the shank IS with its circular plate 26 may be axially journalled in the head member l2, the plate 23 terminates in an upwardly extending axial cylindrical stud 2| serving as a complement of a recess 22. 1

The recess 22 is provided axially through the lower surface H of the head member 12 to communicate with a comparatively larger annular recess 23 sized for journalled telescopic association of the circular plate therewith. In order to retain the shank |3 with its circular plate 20 and axially extending stub 2| within the head member I2 for journalled rotation relative thereto, a circular retaining plate 24 is somewhat larger than the plate 2|! and shaped to cooperate with an annular recess 25 that is somewhat larger than the former adjacent to the annular recess 23 in the lower portion of the head member I2. To this end, the retaining plate 24 has an axial bore 26 provided therein to receive the shoulder IQ of the shank 3 that is journalled therein for support by its stub 2| and shoulder l9 disposed in concentric relation with each other relative to the ends of the shank I8 and the head member l2.

A split retainer ring 21 is mounted in an angular groove 23 provided in the annular recess 25 that is of greater depth than the retainer plate 24 to provide for the angular recess 28 adjacent thereto for reception of the split ring 21 therein. The split ring 21 is sufficiently wide to project within the annular recess 25 to serve as a support and retainer for the plate 24 that is locked in position against the peripheral shoulder 29 formed by the differently sized adjacent annular recesses 23-24. Consequently, the locked retainer plate 24 will serve as a support for the shank l8 and engage the circular flange 20 thereof to preclude any axial movement or freedom therein.

It should be noted that the shank G8 has a polygonal extremity 30 fitted, in this instance, with a spherical detent 3| that is provided in an aperture 32 communicating with one face of the polygonal shank extremity 30. The polygonal detent 3| is retained against removal from the lateral aperture 32 by being swaged along its open orifice 33 to permit the spherical detent 33 to project therefrom without any possible removal. A coil spring 34 is confined in the lateral aperture 32 to normally urge the vertical detent 3| outwardly to provide a projecting surface that serves to frictionally engage the wrench socket or other instrumentality turning device having a polygonal recess corresponding substantially with the polygonal extremity 3|] of the shank l8. This arrangement permits the frictional telescopic association and retention of the socket or other nut turning device on the polygonal extremity 30 of the shank |8 for turning therewith.

To enable the ratcheting of th revoluble shank l8 in an opposed direction relative to the head member 12, the circular flange or plate 20 comprising a part of the shank I8 is provided with a plurality of circumferentially spaced apertures 35, in thi instance ten, that extend entirely therethrough for cooperation with a plurality of diametrically oppositely and correspondingly positioned sets of pawls 36-31 and 38-33. Each of the pawls 36-31 and 38-39 are of identical construction as illustrated in Figure 6 and comprise a polygonal shank 40 that merges with a cylindrical body portion 4| having a pawl tooth 42 extending therefrom. The pawl tooth 42 is offset inwardly from the cylindrical body portion 4| to present a cylindrical engaging surface 42 terminating in a circular shoulder 43 at their line of joinder. The shoulder 43 is interrupted as at 44 by an inclined curved surface 45 that extends from the cylindrical body portion 4| to the tip of the pawl tooth 42 to present a camming surface to vertically displace the pawls 4| relative to the apertures 35 provided in the turning member shank plate 20.

As shown, the pawls 35, 31 and 38-39 are freely received in circumferentially spaced vertical bores 46, 41, 48 and 49 that extend through the head member I2 in a direction parallel to its axis and are radially spaced therefrom to communicate with the annular groove 23 in the lower surface thereof. It should be noted that the pawl teeth 42 of the pawls 36-31-33-39 are spaced from the axis of the head member l2 and turning member l8 to correspond with the spacing of the circumferentially spaced apertures 35 in the turning member plate 20 so that the pawls 36, 31, 33 and 33 will be capable of registry therewith depending upon their relative position.

The pawls 36, 31, 38 and 39 are freely journalled and reciprocally mounted within the bores 46, 41, 4'8 and 49 for controlled operation by a directional actuator 5|) which effects their rotation in unison so that they will always extend in the same direction. In other words, the diametrically opposite pawls 35-31 and 38-39 are disposed with their inclined surface 45 of the pawl teeth 42 in a direction to rotate the plate 20 in a clockwise or counterclockwise direction, in this instance to rotate the shank l3 in a clockwise direction (viewed from Figure 1) are correspondingly disposed and these may be reversed by being rotated to reverse their directional position for ratcheting purposes in one or the other of these two directions.

To this end, the pawls 36-33 and 31-39 are circumferentially spaced from each other for a distance corresponding to one and one-half the circumferential distance between the apertures 35 in the revoluble member plate 25 so that when one set of pawls 33-31 are in registry with aligned opposite apertures 35, the other set of pawls 38-35 are elevated and disposed to contact the upper surface of the revoluble member plate 20 in between the apertures 35 of the revoluble plate 26. This affords a double ratcheting bite on the plate 25. In other words, twenty ratcheting positions are possible with ten holes or apertures 35. When one set of ratchets 35-31 have their ratchet teeth 42 engaging the apertures 35 with the forward cylindrical engaging surface 42 against the wall of any two of the apertures 35, the other set of opposite pawls 38-39 will be disposed between the apertures 35 so that they will alternately ride in and out of registry therewith as the operative sets of pawls 36-31 and 38-39 alternately function to intermittently rotate the revoluble member [8 in one direction or the other.

By rotating the pawls 36-31 and 38-39 for an arc of 180 the opposed sets of pawls similarly function to rotate the revoluble member I8 in the opposite direction. The direction of the pawls 36-37 and 38-39 is governed by the directional actuator, in this instance, a circumferentially knurled knob 51 having a handle depending shank 52 that is journaled in a central aperture 53 provided in the circular top retaining plate 54. The top retaining plate 54 is held in position for attachment to the top surface l6 of the head member l2 by means of suitable fasteners such as rivets 55 and 56, in this instance two, that project through oppositely disposed apertures in the cover retainer plate 5G for pressed-fit into somewhat smaller recesses 57-58 provided through the top surface H5 in the head member l2.

As shown, the head member I2 has a central shallow circular depressed recess 59 that freely receives a gear 6% therein. The gear 65 is attached to the lower reduced extremity 6i of the actuator shank 52 for rotation therewith. The gear 85 meshes with comparatively smaller pinions 62, 63, 6G and $5 that are freely received in somewhat larger shallow recesses 66, fill, 58 and 59,

respectively. The shallow recesses 56, iii, 63, and 69 are provided in the upper surface iii of the head member 2 to communicate with the recess 59 and provide a communication therebetween so that the gears 62-bit and 6 3-65 will mesh with the central actuator gear 6! to control the position of the pawls 31-38 and Bil-til, respectively. To this end, the pinions 52-63 and 54-35 each have polygonal central apertures that freely receive correspondingly shaped polygonal extremities 353 provided on the cylindrical bodies (H of each of the pawls 36, El, 38 and 39.

The direction of the pawls 3%, 3i, 33 and 3a are pre-set to be on oppositely disposed sets 38-31 and 38-39 with the pinions 62-53 and 64-85 extending only for a partial circumference so that they will urge them exactly 180 responsive to the corresponding extent of rotation imparted by the forefinger and thumb of the attendant to the knurled knob 5| of the actuator 50. It will thus be apparent, therefore, that the pawls 36, 3?, 38 and 322 will be free to register vertically relative to the pinions 62-63, 55-65 and these pawls are normally urged downwardly to engage the apertures 35 or the top surface of the revoluble member plate 2% between the apertures 35 responsive to coil springs 76.

The coil springs ill throughout the polygonal extremities ill of each of the pawls 36, 31, 38 and 39, are disposed between the shoulders formed by a somewhat larger cylindrical body portion li thereof and their pinions 62-63-54-65. To permit reciprocation of the pawls 36, 31, 38 and 39 relative to the top closure retainer plate 54, the latter is provided with a plurality of apertures H, in this instance four, that are somewhat larger than and axially aligned with the polygonal extremities as of the pawls 36-3? and 38-39 to maintain the parts in assembled relation and still permit the vertical elevation and descent of .the pawls 36-37-38-39 responsive to the urge of the coil springs 70.

It will be apparent, therefore, that a very .efiective, simple and dependable ratchet mechanism has been provided ina head member of any suitable instrument such as a standard or special wrench. In the present embodiment, the head member 12 is maintained substantially stationary except for slight rotary movement permitted by the flexing of the torque resisting beam II that measures the amount of torque that is applied in nut turning or other situations. For that matter, the head member [2 may remain totally stationary in any other type of instrumentalities and it is only purposed to enable the nut or other fastening expedient to be turned or ratcheted intermittently by the revoluble member ii? that is rotated relative to the head member [2.

Various changes may be made in the embodiment of the invention herein specifically described without departing from the invention or sacrificing any of the advantages or features thereof, and nothing herein shall be construed as limitations upon the invention, its concept or structural embodiment as to the whole or any part thereof except as defined in the appended claims.

We claim: i 1. In a device of the character described, the combination with a handle, of a head member associated with said handle, a revoluble member journalled in said wrench head member, a circumferential series of ratchet elements in one of said members, a lesser number of circumferentially spaced pawls constituting diametrically opposed sets in the other of said members to confront said ratchet elements, all of said pawls be ing positioned in a corresponding direction for cooperative effort in one direction of member rotation, and means for simultaneously displacing all of said pawls relative to said ratchet elements to control the direction of ratcheting said revoluble member relative to said head member. 2. In a device of the character described, the combination with a handle, of a head member associated with said handle, a revoluble member journalled in said wrench head member, there being a circumferential series of ratchet elements in one of said members, a lesser number of circumferentially spaced pawls constituting diametrically o-pposed sets in the other of said members to confront said ratchet elements, all of said pawls being positioned in a corresponding direction for cooperative eifort in one direction of member rotation, and means for displacing all of said pawls relative to said ratchet elements to control the direction of ratcheting said revoluble member relative to said head member. 3. In a device of the character described, the combination with a handle, of a head member associated with said handle, a revoluble member journalled in said wrench head member, a circumferential series of ratchet elements in one of said members, a lesser number of circumferentially spaced pawls constituting diametrically opposed sets in the other of said members to confront said ratchet elements, all of said pawls being positioned in a corresponding direction for cooperative effort in one direction of member rotation, and an actuator operatively connected to said pawls for simultaneously displacing all of said pawls relative to said ratchet elements to control the direction of ratcheting said revoluble member relative to said head member. l. In a device of the character described, the combination with a handle, of a head member associated with said handle, a revoluble member journalled in said Wrench head member, there being a circumferential series of ratcheting apertures in one of said members, a lesser number of circumferentially spaced pawls constituting diametrically opposed sets in the other of said members to confront said ratcheting apertures, all of said pawls being positioned in a corresponding direction for cooperative effort in one direction of member rotation, and an axially disposed actuator operatively connected to said pawls for displacing all of said pawls relative to said ratchet elements to control the direction of ratcheting said revoluble member relative to said head member.

5. In a device of the character described, the combination with a handle, of a head member associated with said handle, a revoluble member journalled in said wrench head member, there being a circumferential series of ratcheting elements in one of said members, a lesser number of circumferentially spaced pawls in the other of said members to confront said ratcheting elements, certain of said pawls comprising sets disposed for engagement with said ratcheting elements for turning the revoluble member in one direction, other of said pawls comprising sets disposed intermediate said ratcheting elements, and means for displacing all of said pawls relative to said ratcheting elements to control the direction of ratcheting said revoluble member relative to said head member.

6. In a device of the character described, the combination with a handle, of a head member associated with said handle, a revoluble member journalled in said wrench head member, there being a circumferential series of ratcheting apertures in one of said members, a lesser number of circumferentially spaced pawls in the other of said members to confront said ratcheting apertures, certain of said pawls comprising sets disposed for engagement with said ratcheting apertures for turning the revoluble member in one direction, other of said pawls comprising sets disposed intermediate said ratcheting apertures, said sets of pawls being circumferentially spaced from each other so that when one set of pawls are in registry with said apertures the other of said sets of pawls are between said apertures to provide for multiple ratcheting, and means for displacing all of said pawls relative to said ratchet elements to control the direction of ratcheting said revoluble member relative to said head member.

'7. In a device of the character described, the combination with a handle, of a head member associated with said handle, a revoluble member journalled in said wrench head member, a circumferential series of ratchet elements in one of said members, a lesser number of circumferentially spaced pawls in the other of said members to confront said ratchet elements certain of said pawls comprising sets disposed for engagement with said ratcheting operation for turning the revoluble member in one direction, other of said pawls comprising sets disposed intermediate said ratcheting apertures, and an actuator operatively connected to said pawls for displacing all of said pawls relative to said ratchet elements to control the direction of ratcheting said revoluble member relative to said head member,

8. In a device of the character described, the combination with a handle, of a head member associated with said handle, a revoluble member journalled in said wrench head member, a circumferential series of ratchet elements in one of said members, a lesser number of circumferentially spaced pawls in the other of said members to confront said ratchet elements, certain of said pawls comprising sets disposed for engagement with said ratcheting operation for turning the revoluble member in one direction, other of said pawls comprising sets disposed intermediate said ratcheting elements, said sets of pawls being circumferentially spaced from each other so that when one set of pawls are in registry with said apertures the other set of pawls are between said aperture to provide for multiple ratcheting, and an actuator operatively connected to said pawls for displacing all of said pawls relative to said ratchet elements to control the direction of ratcheting of said revoluble member relative to said head member.

9. In a device of the character described, the combination with a handle, of a head member associated with said handle, a revoluble member journalled in said wrench head member, a circumferential series of pawl engaging apertures in one of said members, a lesser number of circumferentially spaced pawls in the other of said members to confront said ratchet elements, certain of said pawls comprising sets disposed for engagement with said ratcheting apertures for turning the revoluble member, other of said pawls comprising sets disposed intermediate said ratcheting elements to provide for multiple ratcheting relative to said apertures, said oppositely disposed sets of pawls being circumferentially spaced from each other so that when one set of pawls are in registry with said apertures the other of said sets of pawls are between said apertures, and an actuator geared to each of said pawls for displacing all of said pawls relative to said ratchet elements to control the direction of ratcheting said revoluble member relative to said head member.

10. In a device of the character described, the combination with a head member, of a revoluble member journalled in said head member, said revoluble member having an enlarged circular flange, there being a circumferential series of apertures in said circular flange, oppositely positioned sets of pawls journalled in said head member in the path of the apertures in said revoluble member flange, said sets of pawls being circumferentially spaced so that when one set is in registry with apertures in said circular flange the other set is disposed between apertures, and means in said head member to rotate said pawls back and forth within an angular are.

11. In a device of the character described, the combination with a head member, of a revoluble member journalled in said head member, said revoluble member having an enlarged circular flange, there being a circumferential series of apertures in said circular flangaoppositely positioned sets of pawls journalled in said head member in the path of the apertures in said revoluble member flange, said sets of pawls being circumferentially spaced so that when one setis in registry with apertures in said circular flange the other set is disposed between apertures, springs surrounding said pawls to urge them toward said revoluble member circular flange, and means in said head member to rotate said pawls back and forth'withinan angular arc.

12. In a device of the character described, the combination with a head member, of a revoluble member journalled in said head member, said revoluble member having an enlarged circularflange, there being a circumferential series of apertures in said circular flange, oppositely positioned sets of pawls journalled in said head member'in the path of the apertures in said revoluble member flange, said sets of pawls being circumferentially spaced so that when one set is in registry with apertures in said circular flange the other set is disposed between apertures, springs surrounding said pawls to urge them toward said revoluble member circular flange, and axially disposed actuator means in said head member, gears interposed between said actuator and said pawls to rotate said pawls back and forth within an angular are responsive to said actuator.

13. In a device of the character described, the combination with a head member, of a revoluble member journalled in said head member, said revoluble member having an enlarged circular flange, there being a circumferential series of ratchet elements in said circular flange, oppositely positioned sets of pawls journalled in said head member in the path of the ratchet elements in said revoluble member flange, said sets of pawls being circumferentially spaced so that when one set is in registry with ratchet elements in said circular flange the other set is disposed between ratchet elements, and means in said head member to rotate said pawls back and forth within an angular arc.

14. In a device of the character described, the combination with a head member, of a revoluble member journalled in said head member, said revoluble member having an enlarged circular flange, there being a circumferential series of ratchet elements in said circular flange, oppositely positioned sets of pawls journalled in said head member in the path of the ratchet elements in said revoluble member flange, said sets of pawls being circumferentially spaced so that when one set is in registry with ratchet elements in said circular flange the other set is disposed between said ratchet elements, springs surrounding said pawls to urge them toward said revoluble member circular flange, and means in said head member to rotate said pawls back and forth within an angular arc.

15. In a device of the character described, the combination with a head member, of a revoluble member journalled in said head member, said revoluble member having an enlarged circular flange, there being a circumferential series of ratchet elements in said circular flange, oppositely positioned sets of pawls journalled in said head member in the path of the ratchet elements in said revoluble member flange, said sets of pawls being circumferentially spaced so that when one set is in registry with ratchet elements in said circular flange the other set is disposed between said ratchet elements, springs surrounding said pawls to urge them toward said revoluble member circular flange, and axially disposed actuator means in said head member, gears interposed between said actuator and said pawls to rotate said pawls back and forth within an angular are responsive to said actuator.

KENNETH R. LARSON. GEORGE M. WALRAVEN. 

